Ignition apparatus



June 3, 1930. Y Vs.. ARMITAGE 1,761,512

IGNITION APPARATUS Filed March 15, 1929 ...SEL

N 4 xi Patented June 3, 1930 UNITED STATES PATENT OFFICE SYLVESTERARMITAGE, F DETROIT, MTCHTG'AN, ASSIGNOR T0 GENERAL MOTORS COR-PORATION, 0F DETROTT, MICHIGAN, A CORPORATION 0F DELAWARE IGNITIONAPPARATUS Application filed MarciL 15, 1929.

This invention relates to improvements in ignition devices for internalcombustion engines, and particularly to such devices adapted to vary thetiming of the sparking impulses for said engines.

It is among the objects of the present invention to provide a deviceadapted automatically to control the time of sparking impulses inaccordance with the speed of the 5,0 engine. f

A further object is to provide a device capable of adjusting theaforementioned speed control device in accordance with the temperatureconditions of the engine.

Further objects and advantages of the present invention will be apparentfrom the following description, reference` being had to the accompanyingdrawings, wherein a preferred form of embodiment of the present 2oinvention is clearly shown.

In the drawings:

Fig. l is a plan View of a timer distributor mechanism having thedistributor head and rotor removed.

Fig. 2 is an enlarged fragmentary, sectional view taken along the line 22 of Fig. 3, showing the method of pivotally supporting the centrifugalelement.

Fig. 3 is a vertical, sectional view taken 30 through the ignitiondevice.

Fig. 4L is a fragmentary View showing the centrifugal member and theadjusting means therefor. f

Fig. 5 is a detail View of the timer cam unit to which is secured thedependent ad- Vance cam member which coactsl with the centrifugal ringto change the angular relation between the timer cam and its driveshaft;

Fig. 6 is a detailed, fragmentary view showing the one end of thethermostatic element to which one end of the coil spring of thecentrifugal member is attached.

Referring to the drawings and particularly to Fig. 3, the ignitiondevice is shown comprising a cup-shaped casing 20, having a tubularextension 21, which is adapted to fit into a recess provided in the bodyof the engine for supporting the ignition device is upon said engine. Atubular extension 22,

Serial No. 347,432.

coaxial with the extension 21, is inside the casing 2O and provides foran elongated bearing in which the shaft 23, driven by the engine, isjournalled. Shaft 23 has a portion 24 of lesser diameter than theportion of the shaft journalled in the bearings 2l and 22.

A collar 25 is secured to the drive shaft 23 by a pin 26, which extendsthrough the shaft and collar. Collar 25 has a depending annular flange27, which surrounds the upper end of the bearing extension 22, as shownin Figs. 2 and 3. Diametrically opposite openings 28 are provided in theannular flange 27 of the collar 25, these openingsZ being substantiallycoaxial in alignment and being adapted to receive the reduced ends ofpivot pins 29, which are secured in the cen* trifugal member 30 andpivotally support said member on the collar 25. From this it may be seenthat the centrifugal member 30 rotates with the engine driven shaft 23,for said member is carried by the collar 25 which is secured to shaft 23by the cross pin 26. Centrifugal member 3() has a screw 31 provided witha reduced extension 32 at its other end which extends beyond the innersurface of the ring or centrifugal member 30.

Upon shaft portion 24 which, as has been mentioned heretofore, is oflesser diameter than the shaft portion-journalled in the bearings 21 and22, there is mounted the distributor rotor 33 and the timer cam 34, apin 35 connecting the cam with the rotor so that they are rotated inunison. `Both the cam and rotor are rotatably supported upon the shaftportion 24. To the end of the cam 34, adjacent the collar 25, there issecured a member 36 having an arcuate skirt portion 37, which issubstantially concentric with the aXis of the pivot pins 29 of thecentrifugal member 30. In this arcuate skirt 37 there is provided a slot38 angular to the axis of the shaft 23, into which the reduced portion32 0f screw 3l extends, said screw being carried by the centrifugallmember 30. The slot 38 is angular to the path in which portion 32 ofscrew 3l moves when the centrifugal member 30 is moved about its pivotpins 29 so that, as the portion 32 of the screw 31 moves through theangular slot 33, the member 36,

2G upon the ring.

35 temperatures respectively.

secured to cam 34, will be rotated relative to shaft 23 and thus, cam 34is rotated relative to said shaft 24, so that the time of sparkingimpulses is altered in accordance with the I, movement of thecentrifugal member 30.

In Fig. 1, the circuit interruptor, operated by cam 34, is illustrated.rihis interrupter comprises a movable Contact 40 supported on arm 41pivoted on the pin 42, the arm having a rubbing block 48 maintained inen Oavement D D with the cam 34 by a spring 44. lli/lovable contact 40coopera-tes with the stationary contact 45 supported on the bracket 4G.

One of the pivot pins E29 supports a disk 50 which is cup-shaped, theperipheral edge of pin which supports the disk 50. One end of the coilspring is anchored to an end of the cross pin 26 extending beyond thecontines of the collar 25. The other end of the sprintf t() is attachedto one end of the thermostatic so member 6l. The opposite end of saidthermostatic member is secured to a pin G2 carried by the disk 50. Thethermostatic member (il is made of bimetal and is adapted to eipand andcontract with increasing and decreasing The end of the thermostaticmember 6l to which spring 50 is secured has an angular ear 63 whichentends into and through an opening G4 in the outer face of the disk 50,said opening being of a py predetermined length, whereby the movement ofthe thermostatic member 6l will be limited.

The tension of the spring G0 may initially be set as desired through themanual operation of the disk 50. If the tension of the spring is to beincreased,` pivot pin 2S) is unscrewed, thereby releasing the disk whichmay then be rotated in the proper direction to increase the tensionofthe spring GO. .Vnen

50 the proper tension is attained, the pivot screw 29 is again tightenedcausing the serrations 51 to bite into the ring 30 and thus maintain thedisk in the properly adjusted position. The thermostat automaticallyadjusts the 55 tension of the, spring in accordance with the temperatureof the engine. lt has been found that a cold engine will startmorequickly, run better, and idle more smoothly if the time of sparkingimpulses is advanced bece` yond the limits allowable when the engine iswarm. For this reason, the thermostathas been provided for adjusting thecentrifugal device, said thermostat being affected by i creasingltemperatures of the engine to in- 5 crease the tension of the springwhereby the centrifugal element may move through a proper range toadjust the time of sparking impulses for a warm engine. On the otherhand, when the engine is cold, the thermostat 6l will be affected todecrease the spring tension permitting the centrifugal member to movemore freely to a greater spark advancing position and thus, the time ofsparking impulses will be advanced to a substantially greater degreethan for normal warm engine operation.

The present invention provides for the automatic adjustment of the sparktiming device, whereby the time of sparking impulses may be properly setfor varying engine temperatures and thus more eiiicient engine operationis obtained.

While the form of embodiment of the present invention as hereindisclosed, constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

lvlhat is claimed is as follows:

l. iin ignition device for an internal combustion engine comprising, incombination, a timer; speed controlled means for adjusting the timer tovary the time of sparking impulses in accordance with engine speeds;yieldable means normally urging the speed controlled means toward thespark retarding position; and thermostatic means adapted to vary thetension-of the yieldable means in accordance with the enginetemperatures.

2. An ignition device for an internal combustion engine comprising, incombination, a timer; speed controlled means for adjusting the timer tovary the time of sparking impulses in acccordance with engine speeds; acoil spring normally urging the timer adjusting means toward the normal,spark retarding position; and means controlled by varying enginetemperatures for varying the tension of the coil spring in accordancewith said engine temperatures.

An ignition device for an internal combustion engine comprising, incombination, a timer; speed controlled means for adjusting the timer;and means operable at varying en gine temperatures to vary the effect ofthe speed controlled means.

4. An ignition device for an internal combustion engine comprising, incombination, a timer; a centrifugal governor for automatically adjustingthe timer in accordance with varying engine speeds; a spring urging thecentrifugal governor toward the normal spark retarding position;manually operable means for adjusting the tension of the spring; andthermostatie means adapted automatically to change the tension of thespring in accordance with engine temperatures.

5. An ignition device for an internal combustion engine comprisingl incombination, a timer including a circuit interrupter and u cam foroperating it; an engine driven shaft; a speed governor carried on anddriven by said shaft said governor connecting the cam with the shaft andbeing adapted to rotate the cam relative to said shaft in accordancewith the speed of the engine for varying the time of sparking impulses;a spring urging the speed governor into the normalI spark retardingposition; a manually operable member for adjusting the tension of thespring; and a thermostatic element interposed between the manuallyoperable member and the spring automatically varying the tension of thespring in accordance with engine temperatures.

6. An automatic spark timingdevice for an internal combustion engine,comprising in combination, an engine driven shaft; a cam l supported onsaid shaft so as to be rotatable relative thereto; a circuit interrupteradapted to be operated by said cam; centrifugally operated meanspivotally carried by the shaft and having provisions for connecting thecam with the shaft; said means being adapted, in response to varyingspeeds of the engine, to alter the angular position of the cam relativeto the shaft; a spring yieldably urging the centrifugal means intonormal position; and temperature controlled means for varying thetension of said spring in accordance with temperature conditions.

7 An automatic spark timing device for the ignition system of aninternal combustion engine, comprising in combination, an engine drivenshaft; a breaker cam rotatably mounted on said shaft; an arcuate memberprovided with a spiral slot, secured to the cam; a sleeve` secured tothe drive shaft; a centrifugal member pivotally secured to the sleeveand operatively connected With the spiral slot of the arcuate member; aspring anchored at one end of the sleeve; a thermostatic member anchoredat one end to the centrifugal member and at the other end to the freeend of the spring whereby temperature changes will vary the tension ofthe spring which normally urges said centrifugal member into sparkretarding position.

8. An automatic spark controlling device for an internal combustionengine, comprising in combination7 a drive shaft; a cent-rif ugal memberpivotally mounted thereupon; a coil spring urging said centrifugalmember into normal position; means for manually adjusting the tension ofsaid coil spring; and means for automatically adjusting the tension ofsaid coil spring in accordance with temperature conditions.

9. An automatic spark controlling device for an internal combustionengine, comprising in combination, a drive shaft; a centrifugal memberpivotally mounted thereupon; a disc supported by one of the pivots ofthe centrifugal member so that it Will move with said member; a coilspring adapted to urge the centrifugal member into normalI position saidspring having one end anchored to the drive shaft; thermostatic meanssecured at one end to the free end of the spring the other end of thethermostatic member being anchored to the disc whereby the tension ofthe spring may be varied automatically by the thermostatic means inaccordance with temperature changes or by the manual adjustment of thedisc.

l0. An ignition device for an internal combustion engine comprising incombination: a circuit interrupter; a. cam for operating saidinterrupter; a drive shaft; and temperature responsive means forconnecting the drive shaft and cam and for varying the angular rela-tionbetween them.

il. An ignition device for an internal combustion engine comprising incombination: a circuit interrupter; a cam for operating saidinterrupter; a drive shaft; and devices responsive to varyingtemperature and engine speeds for connecting the drive shaft and cam andfor varying the angular relation between them in accordance with suchtemperature and speed variations.

ln testimony whereof I hereto aliix my signature.

SYLVESTER ARMITAGE.

